The invention relates to a branch saddle of thermoplastic material suitable for use in a pipeline to be repaired or renovated, said pipeline having at least one branch pipe connected therewith through a branch pipe opening, said saddle at least comprising a saddle plate and a branch being accomodated from the inner side of the pipeline into said branch pipe and branch opening.
Such a saddle of a thermoplastic is known in the art.
It presents some disadvantages. First of all the length of the branch of the saddle must be held as small as possible in order to be able to transport the saddle through the pipeline to the position of the branch pipe. This involves the use of a branch of an unacceptable short length in case of small differences in diameter of the pipeline and the branch pipe.
Secondly the branch of the saddle is often too rigid so that it is difficult to accommodate the saddle in the right position in the branch.
Thirdly, the production of such saddles is difficult and at last, the saddle must meet close tolerances.
It is now the aim of the invention to provide a saddle overcoming these disadvantages.
This aim is attained by mean that the saddle is divided in two saddle portions comprising a saddle part and a branch part being movable with respect to each other, thus allowing transport of the saddle through the pipeline for accommodation of the saddle with a decreased projecting length of the branch in comparison with the projecting length of the branch in its final accommodated state.
By using a branch saddle designed in two parts the length of the branch can be increased as the branch is able to move towards the direction below the saddle plate.
Moreover, due to the higher flexibility of the branch with respect to the saddle plate the branch can be more easily pushed into a branch pipe.
A branch saddle according to subclaims 1 to 7 present the advantages of a good flexibility between saddle plate and branch.
Simple production and accommodation of the saddle is possible by means of a saddle having a saddle plate with an integral first conical connecting saddle part which forms a first saddle part and branch having formed thereon a second connecting part forms a second saddle part second conical connecting part being detachably accommodated in first conical connecting part and provided with means for sealingly interconnecting first connecting part and second connecting part.
Flexibility is even more improved by means of a saddle in which the second connecting part is rounded preferably spherical and the saddle portion engaging said rounded, preferably spherical part is conically narrowing towards its free end.
The invention also relates to a repaired or renovated pipeline with at least one branch pipe having a branch pipe inner wall, interconnected by means of a branch pipe opening in which an external surface of a branch saddle inserted from the inner side of the pipeline is made to mate in a sealing manner by sealing means, with the inside of an opposite-lying pipe wall and the branch of this branch saddle extends into a branch pipe while fixing means mating with a pipe wall and the pipe saddle fix the pipe saddle.
Such a renovated or repaired pipeline is known, in particular a sewer pipe in which a tubular lining is pushed from the outside and a branch saddle is pushed outwards from the inside of the pipeline through a bore in the lining. In this case the saddle is drawn from the outside against the tubular lining by means of a moving nut, fitted on an external thread of the branch of the saddle, and a shoulder element.
This known method has the great disadvantage that a pit virtually always has to be dug to form the branch connection, since it is difficult to form the branch connection in existing underground branch pipes; as generally occurs in the case of existing sewer pipes of concrete and the like.
Besides, in the event of use of such a branch connection without digging, a considerable reduction in the existing throughput from or to the existing branch pipe will occur.
Finally, in the case of the known branch connection there is no guarantee of a good seal being obtained between plastic saddle and plastic lining, so that medium such as effluent conveyed through such pipelines can penetrate into the space between tubular lining and inside of the pipeline.
Since, however, it is just such tubular linings which are fitted in sewer pipes which over the years have become damaged, this is unacceptable from the environmental point of view.
Besides, for sewer pipes lying below ground water level, the existing undesirable situation that soil particles and water wash into the pipe through leakage, with risks of sagging and undesirable strain on sewage treatment plants, is not, or is inadequately, eliminated.